1. Field of the Invention
The present invention relates to a method of crushing and breaking casting objects of long objects or the like, a structure of a cutter used for the method and crushing-breaking apparatus of casting products.
2. Description of the Related Art
The applicant discloses a method of crushing and breaking (breaking) of casting products of the title in Japan and the United States of America or Europe (referred to as outline (1)). With regard to outline (1), there are disclosed Japanese Patent Laid-Open No.106083/1994 ‘An apparatus for crushing-breaking weirs, runners, failed products or the like for casting by hydraulic pressure’, Japanese Patent Laid-Open No.182238/1994 ‘A method of crushing-breaking weirs, runners, failed products for casting comprising nonuniform objects, U.S. Pat. No. 5,791,573 ‘CRUSHING-BREAKING APPARATUS’ and European Patent Laid-Open No.0919283 ‘An apparatus for crushing-breaking useless casting products using a fixed and a rocking cutter device and method for coating said cutting devices’.
According to outline (1), there are provided one and other cutter apparatus upper and lower faces of which are open, the one cutter apparatus is provided with a number of pieces of cutters in a mountain-like shape projected in a zigzag shape, the other cutter apparatus is provided with a number of pieces of cutters in a mountain-like shape projected in a zigzag shape and the other cutter apparatus is constituted movably. There is constructed a structure in which in retracting the other cutter apparatus, useless weirs and runners, useless products and the like (referred to as useless products) are charged from a charge opening formed between the one cutter apparatus and the other cutter apparatus and by bringing the cutters in the mountain-like shape of the other cutter apparatus and the cutters in the mountain-like shape of the one cutter apparatus into a fitting relationship, the useless casting products and the like are crushed and broken (broken) and extraction and retraction of the other movable cutter apparatus are automatically controlled by utilizing a cylinder. Further, the broken casting products (casting products to be recycled) are discharged to outside of the apparatus from a discharge opening on the lower side of the apparatus.
Further, the applicant discloses a movable cutter apparatus used in a method of crushing (breaking) casting products in Japan and the United States of America (referred to as outline (2)). With regard to outline (2), there are disclosed Japanese Patent Laid-Open No.106083/1994 ‘A crushing-breaking apparatus of weirs, runners, failed products or the like for casting by hydraulic pressure’ and U.S. Pat. No. 5,791,573 ‘Crushing-Breaking apparatus’.
According to outline (2), there is constructed a constitution in which a strip-like bottom movable cutter apparatus is provided at a discharge opening on a lower side of one and other cutter apparatus. According to the strip-like bottom movable cutter apparatus, in retracting the other cutter apparatus, useless products or casting products to be recycled charged from a charge opening between the other cutter apparatus and the one cutter apparatus, are prevented from dropping.
According to outline (1), as shown by schematic views of FIGS. 12(a) and 12(b) indicating extracting movement of the other cutter apparatus, a bottom side of a cutter of the one cutter apparatus is formed in a planar shape. Further, an upper side of a cutter of the other cutter apparatus is formed in a curved shape. Therefore, when a long object is present between the planar shape on the bottom side and the curved shape on the upper side, there is exerted press force or impact force (referred to as impact force) substantially in the form of face contact, there is a concern that a deficiency in impact force is caused, the object is not broken firmly and smoothly, or the object is escaped and sandwiched between the planar shape on the bottom side and the curved shape on the upper side and is difficult to process, or there poses a problem of damaging the cutter or shortening the life, or there poses a problem of deteriorating the operational efficiency or a problem in view of safety and in view of operational control. Further, as shown by schematic views of FIGS. 12(c) and 12(d) indicating forward movement of the other cutter apparatus, a front end side of a cutter of the one cutter apparatus is formed in a planar shape. Further, also a front end side of a cutter of the other cutter apparatus is formed in a planar shape. Therefore, useless casting objects are exerted with impact force by face contact produced by the two planar shapes and therefore, there poses a problem in which a deficiency in impact force is caused, the useless casting products cannot be broken firmly and smoothly, or the useless casting products are escaped and dropped from between the two planar shapes. Particularly, the tendency is intensified in a large-sized crushing-breaking apparatus, which is a problem to be improved.
Further, according to outlines (1) and (2), it is not intended to operate a charge opening and/or a discharge opening formed at a base end portion on a side of a fulcrum point shaft (support shaft) of the one cutter apparatus and the other cutter apparatus in correspondence with maintenance control of a breaking mechanism, relieving of clogging, change of kind of material and size of charged casting products and breaking dimension and therefore, there is a concern that it is difficult to deal with a failure of the apparatus or interchange the cutter apparatus.